Raisable stepladders



Nov. 25, 1958 R. D. DEAHL ,8

RAISABLE STEPLADDERS Filed June 22, 1955 B Sheets-Sheet 1 i2 1/ 75 i2INVENTOR.

\ H h I I Roy D. DEAHL Nov. 25, 1958 R. D. DEAHL RAISABLE STEPLADDERS 2Sheets-Sheet 2 Filed June 22, 1955 INVENTOR. Roy D. DEAHL RAISABLE'STEPLADDERS Roy D; DeahL NeW York, N. Y.

Application June 22,1955, Serial No. 517 ,123

2' Claims. '(Cl. 228-12) This invention relates to new and,;usefulimprovements in stepladders and elevating devices.

More particularly, the present invention proposes the construction of animproved elevator stepladder which can be used as a low stepladder or asa high stepladder easily and conveniently and at will.

As a further object, thepresentinvention .proposes forming the elevatorstepladder with an upper tread which can be used either as a step ;ortread or -,as a tray forholding buckets, cleaning equipment and othersuch articles.

Another object of the invention-proposes constructing the-elevatorstepladder with aready accessible ;crank so that the user may raise orlower thejladder to suit the particular, need at the time.

Still further, the present invention proposes forming the ladder with aquick release device so that it can be quickly and safely lowered forstepping off the ladder.

For further comprehension of the invention, and of the objects andadvantages thereof, reference will be had to the following descriptionand accompanying drawings, and to the appended claims in which thevarious novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a perspective view of an elevator stepladder constructed andarranged in accordance with the present invention.

Fig. 2 is a rear view of the ladder shown in Fig. 1.

Fig. 3 is a side view of the ladder shown in Figs. 1 and 2 but in raisedposition.

Fig. 4 is a sectional view with parts broken away and taken on line 4-4of- Fig. 3.

Fig. 5 is a front view of an elevator stepladder showing a modificationof the present invention.

The elevator stepladder, in accordance with the first form of theinvention illustrated in Figs. 1 to 4, inclusive, is designed generallyby the reference numeral 15.

Elevator stepladder has a step member 16 with a horizontal lower treadportion 17, a vertical riser portion 18 and a horizontal upper portion19. Preferably the height or length of the riser portion 13 isrelatively great and the horizontal upper portion 19 contains anupturned ledge or flange 20 to make it adapted for use as a table tohold articles thereon such as cleaning equipment, paint buckets and thelike.

A base 21 is provided with rollers or wheels 22 and supports the stepmember in the following manner. An upright support post 23 is mounted onthe base 21, the base 21 being provided with a threaded opening 24 intoand through which the threaded lower end 25 of the post 23 extends. Alock nut member 26 may be provided on the threaded end 25 of the post 23adjacent the base 21.

Slidably mounted on the post 23 is a slide member 27 in the form of asleeve extending over and around the post. A bracket clamp member 28clamped to the slide member 27 and secured to the riser portion 18 ofthe United States Patent '2 step member 16 as by screws 29 secures thestep-member to the slide .member 27.

Upright support post 123 has an axial inner threaded chamber 30 intowhich movably fits a screw column-31 having an upper end 32. extendingfrom the post and 011 which is mounted a screw. column gear 33 which isfixed to the screw, column forzmovement therewith.

Fixed to the horizontal upper portion 1-9 of thestep ,member 16 is aplate 34 from which extends a-dependent and slide: member. gear 37 .to.rotate the gear .37.

Means to-prevent the .slide member 27 from rotating .onlthesupright'support .post323 asthe crank 39 is turned .is .providedlas.follows. A pin. or screw -40 extends through the .wall. of :the .-slidemember 27; into the. axial bore or chamberof the-.upright post 23througha vertical .slot openingsor'. -keyway41-ingthe post.

The. operation -of :-the elevator stepladder is :simple and convenient.:The operaton or :user steps on thelower tread, .orlstep andnworksfromuthat: .tread.0r -s'tept:.when.- a .low .stepladden; is needed."{Ehe upper tray or-:.horizontal portion provides a table to hold workmaterials or can be used as an upper step or tread. When a higher ladderis desired, the crank 39 may be turned which moves the slide member gearwhich in turn moves the screw column gear whichthen turns the screwcolumn and raises the step member. The step member may be lowered byturning the gear crank in the opposite direction.

The modification of the present invention illustrated in Fig. 5 ischaracterized by the provision of an elevator stepladder having a base51 mounted on rollers or wheels 52 with an upright post 53 extendingfrom and fixed to the base. A slide member 54 in the form of a sleeveslidably fits on the post 53 and a step member 55, having a lowerhorizontal tread portion 56, a riser portion 57 and an upper horizontalportion 53, is secured to the-slide member 54 as by bracket 59.

Also mounted on the base 51 is a vertical rack 69 and a pinion 61 forthe rack is rotatably mounted on the rise portion 57 of the step memberas by pillow blocks 62 and 63. A crank 64 is connected to the peripheralportion of the pinion 61 to rotate the pinion on the rack and move it upand down the rack by such rotation. A ratchet pawl 65 is movably mountedon the step member 55 above the pinion 61 and operatively and releasablyconnected with the pinion 61 to limit movement of the pinion in onedirection until released. The ratchet pawl 65 is mounted on a pin orshaft 66 secured by a bracket 67 to the riser portion 57 of the stepmember 55. A spring 68 on the pin 66 biases the ratchet pawl 65 intopinion engaging position.

Post 53 is hollow, having an axial bore or chamber 69 and a pin 70extends from the slide member 54 into and through a vertical slot orkeyway 72 in the post 53.

A bumper spring 73 is mounted in the hollow post with one end 74 hearingagainst the base 51 and the other end bearing against the pin 70. Thespring 73 is of a strength slowly to let the step member descend underthe weight of the user of the ladder after the ratchet pawl is released.This provides a quick and safe means to lower the ladder for steppingofi' the ladder.

While I have illustrated and described the preferred embodiments of myinvention, it is to be understood that Patented Nov. 25, 1958 l theappended claims.

Having thus described my invention, what I claim as new, and desire tosecure by United States Letters Patent 1s right support post mounted onthe base, a tubular slide member slidably mounted on the post, a stepmember connected to the slide member and having a horizontal lower treadportion and a flat vertical riser portion and a horizontal upperportion, means to raise and lower said slide and step members on thepost, said means to raise and'lower said slide and step members on thepost being a vertical rack mounted on the base and a pinion rotatablymounted on the step member and slide member, a crank handle connectedwith the pinion to rotate the pinion on the rack, a ratchet pawl movablymounted on the step member and operatively and releasably connected withthe pinion to limit movement of said pinion in one direction untilreleased, spring means biasing said pawl to operative position, andmeans to prevent the slide member from rotating on the post, said meansbeing a pin extending from the slide member, said post being hollow andhaving a vertical keyway slot slidably to receive one end of said pin.

2. An elevator stepladder comprising a base, an upright support postmounted on the base, a tubular slide member slidably mounted on thepost, a step member connected to the slide member and having ahorizontal lower tread portion and a flat vertical riser portion and 1.An elevator stepladder comprising a base, an up- 7 a horizontal upperportion, means to raise and lower said slide and step members on thepost, said means to raise and lower said slide and said step members onthe post being a vertical rack mounted on the base and a pinionrotatably mounted on the step member and slide member, a crank handleconnected with the pinion to rotate the pinion on the rack, a ratchetpawl movably mounted on the step member and operatively and releasablyconnected with the pinion to limit movement of said pinion in onedirection until released, spring means biasing said pawl to operativeposition, and means to prevent the side member from rotating on thepost, said means being a pin extending from the slide member, said postbeing hollow and having a vertical keyway slot slidably to receive oneend of said pin, and a bumper spring mounted in the hollow post andhaving one end bearing against the base and another end bearing againstsaid pin.

References Cited in the file of this patent v UNITED STATES PATENTS72,329 Rittenhouse. Dec. 17, 1867 114,812 Hartman May 16, 1871 283,851Binsse Aug. 28, 1883 426,267 Greenlow Apr. 22, 1890 554,024 GilbrethFeb. 4, 1896 622,208 Cox Apr. 4, 1899 768,821 Schmick Aug. 30, 19041,314,192 Oppenheim May 25, 1920 1,465,057 Riker Aug. 14, 1923 1,606,101Russell Nov. 9, 1926

